What is the baptism of the Holy Spirit?

From Pentecostal to Presbyterian, This topic never fails to insight lively debates amongst christians from all tribes and tongues.(see what i did there?) "Does it happen to all christians at salvation or is it a subsequent experience? Come to think of it... What even is it??"

This discussion may spark questions, curiosity, or even concerns...But ultimately, our aim is to drive you to the scriptures. Let's get uncomfortable!